Inrush current protection circuit

• Main Author: CHEN CHIN-HOU
• Format: Patent
• Language: English
• Published: 19.12.2002
• Edition: 7
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS; GENERATION

The invention relates to an inrush current protection circuit for a power supply. The power supply includes a rectification circuit coupled to a main body of the power supply through an energy-storage capacitor. The main body of the power supply is provided with a reference voltage, and the setup time of the reference voltage is greater than a threshold value. The inrush current protection circuit includes a current limiting resistor coupled between a negative terminal of the rectification circuit and a ground terminal of the energy-storage capacitor for preventing the generation of an inrush current the instant that the power supply is powered on, and a switch coupled in parallel with the current limiting resistor and which is controlled by the reference voltage. When the reference voltage is set up, the switch switches from an open state to a short state, so as to bypass the current limiting resistor.